The municipality of Marijampole borders with the district of Vilkaviskis in the west, Kazlu Ruda Municipality in the north, Kalvarija Municipality in the south, and districts of Prienai and Alytus in the east.

The centre of the municipality is Marijampole, the largest town in Suduva (Suvalkija) region. It is the seventh biggest town in Lithuania, the centre of the county situated on both banks of the Sesupe river. The distance from Marijampolė to Vilnius is 139 km, to Klaipeda - 231 km, and to the border of Poland - 38 km.

The municipality is located at the intersection of very important highways. One of them, Via Baltica, after the reconstruction will join Helsinki (Finland) with Central and Southern Europe. The other highway connects Kaliningrad to Moscow via Minsk (Byelorussia). Marijampole town has a convenient connection to other towns of Southern Lithuania. There is a railway Kaunas-Sestokai-Alytus passing through Marijampole.

The town of Marijampole and its 6 surrounding communities make the territory of Marijampole municipality. They are: Gudeliai, Igliauka, Liudvinavas, Marijampole, Sasnava, and Sunskai communities. Marijampole municipality covers 75,5 thousand hectares of land; 72% of which is an agricultural area, 12,3% is covered by forests; 4,2% - towns and villages, 2% - industrial enterprises and roads; and 6,9% - the area of other purposes.